Add media-types module with simpleTypeFromSourceType function

README.md

@@ -10,7 +10,12 @@
 
 # @videojs/vhs-utils
 
-Objects and functions shared throughtout @videojs/http-streaming code
+vhs-utils serves two purposes:
+
+1. It extracts objects and functions shared throughout @videojs/http-streaming code to save on package size. See [the original @videojs/http-streaming PR](https://github.com/videojs/http-streaming/pull/637) for details.
+2. It exports functions useful to plugin authors to mimic some logic VHS uses internally.
+
+Note that for the case of 2, although the functions are exported, they may change at any time, although appropriate semantic versioning of this module will be maintained.
 
 ## Installation
 

src/media-types.js

@@ -0,0 +1,36 @@
+const MPEGURL_REGEX = /^(audio|video|application)\/(x-|vnd\.apple\.)?mpegurl/i;
+const DASH_REGEX = /^application\/dash\+xml/i;
+
+/**
+ * Returns a string that describes the type of source based on a video source object's
+ * media type.
+ *
+ * @see {@link https://dev.w3.org/html5/pf-summary/video.html#dom-source-type|Source Type}
+ *
+ * @param {string} type
+ * Video source object media type
+ * @return {('hls'|'dash'|'vhs-json'|null)}
+ * VHS source type string
+ */
+export const simpleTypeFromSourceType = (type) => {
+ if (MPEGURL_REGEX.test(type)) {
+ return 'hls';
+ }
+
+ if (DASH_REGEX.test(type)) {
+ return 'dash';
+ }
+
+ // Denotes the special case of a manifest object passed to http-streaming instead of a
+ // source URL.
+ //
+ // See https://en.wikipedia.org/wiki/Media_type for details on specifying media types.
+ //
+ // In this case, vnd is for vendor, VHS is for this project, and the +json suffix
+ // identifies the structure of the media type.
+ if (type === 'application/vnd.vhs+json') {
+ return 'vhs-json';
+ }
+
+ return null;
+};

test/media-types.test.js

@@ -0,0 +1,41 @@
+import QUnit from 'qunit';
+import { simpleTypeFromSourceType } from '../src/media-types';
+
+QUnit.module('simpleTypeFromSourceType');
+
+QUnit.test('simpleTypeFromSourceType converts HLS mime types to hls', function(assert) {
+ assert.equal(
+ simpleTypeFromSourceType('aPplicatiOn/x-MPegUrl'),
+ 'hls',
+ 'supports application/x-mpegurl'
+ );
+ assert.equal(
+ simpleTypeFromSourceType('aPplicatiOn/VnD.aPPle.MpEgUrL'),
+ 'hls',
+ 'supports application/vnd.apple.mpegurl'
+ );
+});
+
+QUnit.test('simpleTypeFromSourceType converts DASH mime type to dash', function(assert) {
+ assert.equal(
+ simpleTypeFromSourceType('aPplication/dAsh+xMl'),
+ 'dash',
+ 'supports application/dash+xml'
+ );
+});
+
+QUnit.test(
+ 'simpleTypeFromSourceType does not convert non HLS/DASH mime types',
+ function(assert) {
+ assert.notOk(simpleTypeFromSourceType('video/mp4'), 'does not support video/mp4');
+ assert.notOk(simpleTypeFromSourceType('video/x-flv'), 'does not support video/x-flv');
+ }
+);
+
+QUnit.test('simpleTypeFromSourceType converts VHS media type to vhs-json', function(assert) {
+ assert.equal(
+ simpleTypeFromSourceType('application/vnd.vhs+json'),
+ 'vhs-json',
+ 'supports application/vnd.vhs+json'
+ );
+});